Method of making highly stretchable textile yarn



N. HADDAD Oct. 23, 1945.

METHOD OF MAKING HIGHLY STRETCHABLE TEXTILE YARN Filed. Nov. 22 1944 i INVENTbR. H 4446 075 7940049 Arromvy Patented Oct. 23 ,1945' OFFICE" METHOD OF .MAKING HIGHLY STRETCHABLE TEXTILE YARN Nassib Haddad, Iselin, N. 3., asslgnor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application November 22 1944, Serial No. 564,566

4 Claims. (@1- 579-160) This invention relates to a method of making an all textile yarn having high stretch characteristic and good contractive action, and more particularly to a method of improving the highly stretchable yarn described and claimed in the Boutwell H. Foster application, Serial No. 548,268 filed August 5, 1944.

High stretch or crepe yarns having a twist two or three times that of ordinary yarns of the same material are well known. These crepe yarns as constructed heretofore have a stretch range up to about 50% and a comparatively weak and slow return, and they are usually difiicult to handle as they tend to buckle, kink and snarl'when relieved from tension. This tendency of such yarns to kink makes them difficult to work and is the cause of much annoyance and loss of time.

The yarn contemplated by the above cited Foster application has an elastic extensibility range that is greater than that of the crepe yarns employed heretofore, and this increase in stretch range is secured without imparting to the yam a serious tendency for the same to kink or snarl.

The said Foster application discloses several different types of all-textile yarn having good stretch characteristics, and one 'of the highly stretchable yarns disclosed in such application is a balanced elastic yarn, formed of a crepe yarn having a large number of helical coi1s, wound in the direction of its twist, and a second crepe yarn twisted in the opposite direction and having a large number of helical coils wound in the direction of its twist over the first helical coils.

' The present invention contemplates a method of improving such balanced stretchable yarn of the Foster application.

In the construction just described of the Foster application the outer yarn is wound over the coils of the inner yarn in direct contact therewith, with the result that the frictional engagement between the outer and inner coils tends to interfere to'some extent with the stretchingand retraction 1 of this highly stretchable yarn.

vided between such inner and outer coils to.

thereby determinethe size of the clearance space between such coils. Then after the operation of winding the outer crepe yarn helically about such cover is completed the temporary cover and the core yarn are destroyed. Thus the desired clean ance space is provided between the remaining inner and outer coiled crepe yarns which together form a balancedryam having high extensibility and good retraction. A yarn constructed in accordance with the present method may have any desired range of stretch, i. e,., extensibility, from 50% to 300% or more.

The above and otherfeatures of the present invention will be more fully understood from the following description when read in connection with the accompanying'drawing illustrating the steps involved in carrying out the present method.

In the drawing: Fig. 1 is a side elevation of an unbalanced coiled I yarn constructed in accordance. with-an initial step employed in carrying out the present method.

Fig. 2 is a side elevation showing the unbalanced yarn of-Fig. 1 after a temporary second cover and a third cover have been wound thereupon; and

Fig. 3 shows theconstruction of Fig. 2 after the core yarn and second cover have been removed to leave a central hole and a clearance space icetween the inner and outer windings of the crepe yarns.

Each crepeyarn used in constructing the highly stretchable yarn contemplated by the present in vention may be formed of a single yarn or of a ply yarn as desired andmay be formed of any preferred or well known textile fibers or filaments, such as cotton, wool, silk, or rayon. Such highly twisted or crepe yarn, designated by iii in they drawing, is shown as a ply yarn formed by twisting together in the usual manner two ordinary single yarns H and giving them a high twist or crepe twist corresponding to a twist multiplier which is preferably from two to three times as high as that of the ordinary yarn of the same material. A high twist corresponding 'to a twist multiplier of from 7 to 8 has been found to-be especially good. The number of twists per unit In carrying out the present method a i length of the yarn It] may, however, vary considerably depending upon the nature and size of the yarn used and the amount of stretch desired in the finished highly stretchable yarn.

In carrying out one step of the present invention the highly twisted or crepe yarn ill is coiled helically in the direction of its twist about a central axis to form the helical coils l2, and it is extremely important that the coils it be wound in the same direction as that in which the yarn I0 is twisted. For example, if the yarn it has an S twist, then the coils I2 likewise should be in the 8 direction.

In the construction shown the crepe yarn it is coiled helically upon a core yarn it. The

core yarn should be formed of a diiferent type of fiber or filament from that of the yarn it) so that the core yarn l3 may be chemically destroyed without injuring the crepe yam id, thus Materials Such second cover may be -rectly about the helical winding l2 of the first' Over this second cover formed of the coils I 5 is wound a highly twisted or crepe yarn It so as to form a third cover'formed of thecoils ll. It is highly important that the twist of the yarn I6 be in the opposite direction to that, of the yarn l and it is also highly important that the helical coils 11 shall extend in the opposite direction to the coils l2, to form the balanced construction shown in Figs. 2 and 3 of the drawing. For ex-' ample, if the twist and the coiling of the yarn ill are in the 8 direction, then the twist and the coiling of yarn it should be in the 2 direction.

The three covering yarns I0, l4, and [6 may conveniently be applied to the core yarn by means of covering machines having one bank of spindles or two or three banks of coaxial spindles, as will be apparent to those skilled in the art.

- The range of stretch inherent in the helically coiled yarn Ill will depend largelyupon the size of the coils I2, and the size of these coils depends upon the size of the core I 3. stretch yarn is desired a large core l3 should be used and when a short-stretch yarn is desired a small core I3 should be used.

After the construction shown in Fig. 2 of the drawing has been formed the core I3 and the second cover l5 are dissolved away so that they will not interfere with the stretching of the helically wound yarns l0 and I6 and so that the desired clearance space is provided between the inner coils l2 and outer coils l'l, thereby lessening the tendency of the coils I2 and I! to inter- When a long fere with each other when the balanced highly stretchable yarn shown in Fig. 3 is stretched or permitted toretract. As a result of this method of construction it. follows that, when the compound yarn'of Fig. 3, comprising the helical coils l2 and I1, is'elongated, the effect will be to increase the twist in the already highly twisted yarns l0 and I6, thus setting up'forces which tend to cause the compound yarn to return.

smoothly to its original length when the tension is released.

In order that the construction contemplated by the present invention may be further understood, the following example is given.

Construction of Fig. 2

Core: 2 ends of 150 den. acetate yarn First cover: 1 end of 80 8/2 cotton yarn of S twist Second cover: 1 end of 150 den. acetate yarn Third cover: 1 end of70 S/2 cotton yarn of Z twist Yarn analysis:

. Yards perpound 1,370 Overall gauge inches .029 Twist of yarn l0, per inch 45S Wraps of. yarn l0, per inch of core l3 1078 Length of yarn III in 1 yd. of covered core yarn inches 158 Twist of yarn it, per inch. 452 Wraps of yarn I6, per inch of core I3 1122 Length of yarn l6 in 1 yd. of covered core yarn inches 320 Construction of Fig. 3

4 Y am analysis:

lithe core l3 and second cover l5 are formed of acetate yarn as indicated in the above example, and each of the first and third covers is formed of either cotton or viscose yarn, then the core l3 and cover l5 may be chemically destroyed without injuring the yarns Ill and I1, by soaking the construction of Fig. 2 in a solvent bath such as acetone and washing the treated yarn with fresh solvent until it is free of soluble cellulose derivative.

A highly stretchable yarn constructed in accordance with the present method will have a long stretch, i. e., high extensibility, and quick elastic recovery, but will have a lower elastic modulus than the usual rubber-covered elastic yarn.' It is well adapted for use in light weight undergarments, bathing suits, tops of stockings, waist bands, 'etc.

Having thus described my invention, what I claim and desire to protect by LettersPatent is:

1. The method of making an all-textile yarn having high stretch characteristics, which comprises winding a crepe twist yarn about a destructible core yarn in the same direction as the twist of the crepe yarn to form a first cover, winding a destructible yarn thereover to form a second cover, winding 2. second crepe twist yarn that is twisted'inthe opposite direction to the first crepe yarn over said second cover in the same direction as the'twist of the second crepe yarn to form a third cover, and thereafter destroying only said core yarn and second cover so that the remaining first and third covers together form a balanced yarn having high extensibility and rapid elastic recovery.

2. The method of making an av -textile yarn having high'stretch characteristics, which comprises winding a crepe twist yarn about a core in the same direction as the twist of the crepe yarn to form a first cover, winding a destructible yarn thereover to form a second cover, winding a second crepe twist yarn that is twisted in the opposite direction to the first yarn over said second cover in the same direction as the twist of the second crepe yarn and opposite in direction .t the windings of the first cover to form a third cover, and removing only said core and second cover so that the remaining first and third covers together form a balanced yarn having high extensibility and rapid elastic recovery.

3. The method of making an all-textile yarn having high stretch characteristics, which comprises winding a crepe twist yarn about a core in the same direction as the twist of the crepe .yarn to form a first cover, winding a yarn thereover to form a second cover, winding 9. second crepe twist yarn that is twisted in the opposite direction to the first yarn over said second cover in the same direction as the twist of the second crepe yarn to form third cover, and removing said core'and second cover to provide a substantial space inside the first cover and a clearance space between the first and third covers so that ii 1,!!! e 3 these two covers together will form a, yarn ha'ving high extensibility and rapid elastic recovery.

4. The method or making an ali-teirtile yarn having high stretch characteristics, which-comprises winding a crepe twist yarn in touching helicai coils about a. core in the some direction as the twist oi. the crepe yarn, winding a. yarn site direction to the first yarn over the second cover in touching helical coils in the same direction as the twist of the second crepe yam to form a'third cover, and removing said core and second cover so that the remaining first and third v covers together form a stretchable yam having an extensibility-of over 100 per cent. thereover to form a. second cover, winding a sec- Y f 0nd crepetwist yarn that is twisted in the oppo- 

